Merck's Keytruda shown to extend lung cancer survival in 2 trials

CHICAGO, June 3 (Reuters) - New trial results show that Merck & Co's Keytruda improves survival as a stand-alone treatment for newly diagnosed lung cancer and in combination with chemotherapy for hard-to-treat squamous cell lung cancer.

The results, presented at the annual meeting of the American Society for Clinical Oncology in Chicago, add to the argument that Keytruda has "set the floor against which other therapies will need to be compared," Roy Baynes, head of clinical development at Merck, told Reuters.

Keytruda, along with drugs like Roche's Tecentriq and Bristol-Myers Squibb's Opdivo, is designed to unleash the body’s immune system to attack cancer cells.

One trial involved 1,274 patients with advanced non-small cell lung cancer who tested positive for the PDL1 protein targeted by Keytruda. It showed that Keytruda patients lived for a median of 16.7 months, compared with 12.1 percent for patients given chemotherapy.

Patient outcomes were linked to the biomarker. Keytruda patients with PDL1 levels over 50 percent lived for a median of 20 months, compared with 12.2 months for those given chemotherapy.

The results show that use of Keytruda alone may benefit more patients than was previously known, said Dr Bruce Johnson, ASCO's president-elect.

Based on results from an earlier, smaller trial, Keytruda is already approved as a stand-alone treatment for lung cancer patients whose tumors have high levels of PDL1. The drug is also approved in combination with chemotherapy as an initial treatment for non-squamous NSCLC.

Merck said it is not yet clear whether Keytruda combined with chemotherapy is better than Keytruda alone in patients who express PDL1.

Severe side effects, including lung inflammation, occurred in 18 percent of Keytruda patients, compared with 41 percent of chemotherapy patients. Merck said Keytruda led to the deaths of 13 trial patients, compared with 14 treatment-related deaths in the chemo group.

Researchers also presented results on Sunday from a second trial of Keytruda in patients with late-stage squamous cell NSCLC, which accounts for about 30 percent of lung cancer and is considered particularly difficult to treat.

The 559-patient trial found that patients given Keytruda plus chemotherapy lived for a median of 15.9 months, compared with 11.3 months for patients given chemotherapy alone.

Merck said Keytruda trial patients lived for a median of 6.4 months before their disease worsened, compared with 4.8 months for the chemotherapy-alone group.

Rival Roche on Saturday said a trial of its immune therapy Tecentriq in combination with chemotherapy showed that the drug delayed progression of squamous NSCLC by 6.3 months, compared with 5.6 months for the standard chemotherapy combination.

Overall survival results for the Roche trial were not yet mature.

In its squamous lung cancer trial, Merck said serious side effects, including anemia and nausea, were seen in 69.8 percent on patients on Keytruda and 68.2 percent patients on chemotherapy alone.

There were 10 treatment-related deaths in the Keytruda combination group and six in the chemotherapy alone group.